import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.interfaces.*;
import java.security.interfaces.*;
import java.math.*;
import java.io.*;
public class Dec_RSA{
    public static void main(String args[]) throws Exception{
        //读取密文
        BufferedReader in=
                new BufferedReader(new InputStreamReader(
                        new FileInputStream("Enc_RSA.dat")));
        String ctext=in.readLine();
        BigInteger c=new BigInteger(ctext);
        //读取私钥
        FileInputStream f=new FileInputStream("Skey_RSA_priv.dat");
        ObjectInputStream b=new ObjectInputStream(f);
        RSAPrivateKey prk=(RSAPrivateKey)b.readObject( );
        BigInteger d=prk.getPrivateExponent();
        //获取私钥参数及解密
        BigInteger n=prk.getModulus();
        System.out.println("d= "+d);
        System.out.println("n= "+n);
        BigInteger m=c.modPow(d,n);//m为明文，c为密文，d为私钥，
        //显示解密结果
        System.out.println("m= "+m);
        byte[] mt=m.toByteArray();
        System.out.println("PlainText is ");
        for(int i=0;i<mt.length;i++){
            System.out.print(" "+mt[i]);
        }
    }
}